221656505373 has 16 divisors (see below), whose sum is σ = 335366818560. Its totient is φ = 144626938848.

The previous prime is 221656505363. The next prime is 221656505423. The reversal of 221656505373 is 373505656122.

221656505373 is a `hidden beast` number, since 2 + 2 + 1 + 65 + 6 + 50 + 537 + 3 = 666.

It is not a de Polignac number, because 221656505373 - 2⁸ = 221656505117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221656505353) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87333840 + ... + 87336377.

It is an arithmetic number, because the mean of its divisors is an integer number (20960426160).

Almost surely, 2^221656505373 is an apocalyptic number.

It is an amenable number.

221656505373 is a deficient number, since it is larger than the sum of its proper divisors (113710313187).

221656505373 is a wasteful number, since it uses less digits than its factorization.

221656505373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174670273 (or 174670267 counting only the distinct ones).

The product of its (nonzero) digits is 1134000, while the sum is 45.

The spelling of 221656505373 in words is "two hundred twenty-one billion, six hundred fifty-six million, five hundred five thousand, three hundred seventy-three".